Conferences are becoming ever more important in the business world. Often it is difficult to reserve properly equipped conference rooms, and often they are at different locations worldwide. For conference participants who are sitting together in one room, often the necessary audio and visual equipment is not physically present in the room, or only some of it is there, or it is not adequately functional, such as only a TV and no camera and/or a regular desktop telephone but no additional speaker function. It is known that stereophonic sound transmission significantly increases the comprehensibility and acceptance of a conference. It can also occur that a camera is poorly placed or has inadequate control features, so that the room is not adequately illuminated and/or some conference participants are not understood or are poorly understood. These conditions are detrimental to the productivity of the conference. In addition, remote participants who are not physically in the conference room but rather are alone in their own workplaces or home offices, or are traveling and have joined the conference call, wish to know who is participating in the conference. Today this is accomplished by means of a brief introduction and verbally listing the participants in the conference room. It is necessary to write down the participants' names in order to have that information available. In the case of a video conference, sometimes only a portion of the participants are visible, so the same information is not available to all conference participants. Participants who are participating individually, and are not sitting in the conference room, call in using a dial-in number.
U.S. Patent Application Publication No. 2013/0106976 describes a video conference system with a conference unit that uses mobile devices in a conference room as peripheral devices in such a way that they receive the audio and visual signals picked up by the microphones and/or cameras of the mobile devices. This means that the loudest audio signal is always sent to a remote participant. To prevent acoustic couplings between the microphones of the mobile devices and the speaker unit of the conference system, an echo canceller is used. If the conference call was originally initiated using the mobile device, the participant can then transfer the conference call to the conference unit in the conference room. After the conference call is transferred to the conference unit, the voice and video outputs are switched to the conference unit's speakers and displays.